Descriptions

Field and laboratory work was undertaken in 1993 to increase understanding of the life history and ecology of the brown jellyfish,
Chrysaora fuscescens, a large semaeostome typically abundant in the neritic regions of the Oregon coast during summer months. Few
medusae were found during 1993, possibly the result of anomalous conditions caused by an El Nino event in that year. Benthic scyphozoan polyps (scyphistomae) were discovered in Yaquina Bay, Oregon, during an extensive underwater survey of the bay using
SCUBA. The distribution of the scyphistomae appears to be related to the availability of suitable substrate, almost exclusively the
rockwork of jetties and breakwaters, suggesting human activity may be largely responsible for periodic "blooms" of scyphozoan jellyfish. Based upon (1), a study of the scyphistomae's nematocyst complement and (2), a rearing experiment of the juvenile medusae (ephyrae) produced by polyps collected while undergoing strobilation, the Yaquina Bay polyps were determined to be the
benthic stage of the moon jelly, Aurelia aurita, a species with a worldwide distribution. Attempts to induce metamorphosis and strobilation in the polyps using techniques developed elsewhere were unsuccessful, suggesting that there may be differences in the cues that trigger metamorphosis in Aurelia collected from various regions.